Virtual reality (VR) is a computer technology that replicates an environment, real or imagined, and simulates a user's physical presence in the environment and, in some cases, enables the user to interact with the environment. Typically, virtual reality content is displayed on a computer monitor or with a virtual reality device such as a virtual reality headset, which is also commonly referred to as a head-mounted display. The user may interact with the environment by interacting with the virtual reality device, through the use of a standard input device such as a keyboard or mouse, or through a multimodal device such as a wired glove. As the user interacts with the environment, three-dimensional (3D) images are provided by virtual reality software that accesses virtual reality content.
The original source images from which VR content is constructed correspond to different perspectives from the user's location within the virtual environment. In the typical work flow by which VR content is generated, these images are combined in a process known as “stitching” to form a two-dimensional (2D) representation (using, for example, polygonal or equirectangular projection) in which each of the images corresponds to a portion of a three-dimensional (3D) shape such as, for example, a cube or a cylinder. The 2D representation is then compressed using any of a variety of encoding techniques such as, for example, H.265/High Efficiency Video Coding (HEVC) or H.264/MPEG-4 Advanced Video Coding (H.264).
A 2D representation generated by a stitcher can include non-display pixels that do not contain image content. As a result, the 2D representation that is encoded can include sharp edges that separate the stitched VR content from regions of non-display pixels. During playback of the VR content, visual artifacts can result, detracting from the user's experience.